• sexual life;
  • epidemiology;
  • carcinoma of the prostate


A case-control study on prostatic cancer was conducted in Kyoto, Japan, from 1981–1984, including 100 patients with prostatic cancer (PC) and age, hospital, and date-of-admission matched controls of benign prostatic hyperplasia (BPH) patients and general hospital patients. Analysis of several sexual factors obtained through a self-administered questionnaire revealed the following observations: (1) cancer patients had fewer sex partners before marriage (relative risk, RR = 0.35; 95% confidence interval: 0.13–0.93 than the hospital controls; (2) they had more vigorous sexual activities in the third (RR = 2.89: 1.01–8.28 and fourth decades of life (RR = 2.26: 1.03–4.95) than hospital controls, but no significantly different sexual activities from controls in other decades; (3) they had less frequent orgasms (RR = 2.55; 1.11–5.83) than BPH controls or (RR = 4.96: 1.78–13.9) hospital controls, and sexual intercourse appeared to be less satisfactory (RR = 2.08: 1.05–4.13) than that of hospital controls; and (4) they had less frequent episodes of sexually transmitted diseases (RR = 0.36: 0.16–0.83) than BPH controls. Marital status, fertility, ejaculation, masturbation, nocturnal emission, contraceptive use, and wife's episodes of sexually transmitted disease were not linked to prostatic cancer risk.